Milling machine



A. B. BACHMANN June 5, 1928,

MILLING MACHINE Filed May 20, 1921 15 Sheets-Sheet l June 5, 1928. 1,672,744

A. B. BACHMANN MILLING MACHINE Filed May 20, 1921 15 Sheets-Sheet 3 June 5, 1928.

A. B. BACHMANN MILLING MACHINE Filed May 20, 1921 .5 Sheets-Sheet 4 15 Sheets-Sheet 5 A. B. BACHMANN MILLING MACHINE Filed May 20,

June 5, 1928'.

$5 WE R a W i i T r 3 7 June 5, 1928.

A. B. BACHMANN MILLING MACHINE Filed May 20, 1921 1.5 Sheets-Sheet 6 TOR.

. ATTORNEYS lIlll/ll/lllll/l I 7/ June 5, 1928.

A. B. BACHMANN MILLING MACHINE Filed May 20. 1921 15 Sheets-Sheet 7 I N VEN TOR.

June 5, 1928. 1,672,744 A. B. BACHMANN MILLING MACHINE F'lled May 20, 1921 15 sheetksheet 8 ii i '7 INVENTOR.

June 5, 1928. 1,672,744

A. B. BACHMANN MILLING MACHINE F'l d M 20. 1921 l e ay 15 Sheets-Sheet 9 A 7 7 M W INVENTO "A TTORNEY.

June 5, 1928.

A. B. BACHMANN MILLING MACHINE Filed May 20, 1921 15 sheets-Shea: 11

ATTORNEYS.

June 5, 1928.

A. B. BACHMANN MILLING MACHINE Filed May 20, 1921 15 Sheets-Sheet l2 I N VEN TOR.

/ A TTORNEYZS June 5, 1928.

A. B. BACHMANN l5 Sheets-Sheet 13 Q QR W 7 INVEN TOR.

June 5, 1928.

A. B. BACHMANN MILLING MACHINE Fil y 1921 15 Sheets-Sheet 14 INVENTOR.

v BY

June 5, 1928 A. B. BACHMANN MILLING MACHINE Filed May 20, 1921 15 Sheets-Sheet 15 4* 4 351254 INVENTOR.

BY I v4' v ATTORNEY.

Patented June 5, 1928.

PATENT OFFICE.

ALWIN IB- BACHMANN, OF BROOKLYN, NEW YORK.

MILLING MACHINE.

Application filed May 20,

This invention relates to milling inachines, and to a method of operation of such machines. As to the machine itself, in invention contemplates, among other ob ects, the provision of a milling machine free from deficiencies which inhere in prior milling machines having a reciprocating or rotating work-table, by which the work is fed in a straight line under the cutting tool and returned to initial position, or continuousl fed in a circular path under the cutting too The prior milling machines referred to comprise several types, which it will be necessary to briefly mention in order to indicate the object of the present invention, just stated.

The prior milling machines here referred to may be classed in two groups--one em ploying a reciprocating work-table, whereby the work-piece is ted in a straight line under the cutting tool and returned in the same path to initial position, and the other employing a rotating work-table, whereby a plurality of work-pieces placed ofi center thereof will be fed in a circular movement under the cutting tool. and which workp eces successively return to initial position where they can be removed and new workpieces placed upon the table.

The development of these machines shows the tendency in the art to reduce the noncutting or non-productive time and to simplify the functions of the operator by performing the different movements of the ta ble automatically. Thus, in both types, the feed has been rendered intermittent, by means of adjustable dogs and co-operating feeding means, whereby the feed or movement of the table under the cutter may be var ed from a slow feed, when a work-piece is in position beneath the cutter. to a fast traverse, to hasten the advance of the next work-piece to the cutter, then a slow feed again while the last-mentioned work-piece is undergoing the cutting operation, and again a rapid traverse to hasten the advance of the next work-piece to cutting pos tion; and. finally, in the case of a reciprocating slide. a rapid return after all the work-pieceshave advanced beyond the cutter, back to the initial position.

\Vhile, in the second type, employing a rotating work-table. work-pieces may be set or removed While the table is rotating and a 1921. Serial No. 471,061.

work-piece passing under the cutter, this type can advantageously be used only with Work-pieces of circular shape or for face milling, since the work-pieces upon the rotating table transcribe a circular path under the cutting tool. Another disadvantage of this type is the necessity of employing numerous work-holding fixtures, the expense. of which is warranted only when milling parts in very large quantities.

A third type has been developed in an endeavor to eliminate the idle time occurring in the tirst type of machine by the necessity of stopping the work-table when setting or removing a work-piece, by the employment of two work-tables mounted upon a swivel, upon one of which the work is being cut While new work is being set upon the other, the two tables being successively swivelled into working relation to the cutter. This third type, however, requires a multiplication of parts which is in itself objectionable and further tends to inaccuracy of work; and moreover, requiring so large a turret for the two swivelling work-tables or so great an overhang of the tables upon the turret as to form a source of inconvenience to the operator.

One of the objects contemplated by the present invention is to provide a single work-table of the reciprocating type in its feed, traverse and return, and to provide means for removing a finished piece of work and setting a new piece while the table is in motion, and without the multiplicity of parts employed in the third type referred to.

Another object of the present invention is to provide in one machine the various movements of the work in feed. traverse and return hithertofore possible only in the several types of machines of the prior art, and thereby to combine in one compact machine the certain distinct advantages of the several types of the prior art. Thus, each of the heretofore-meiitioncd types of machine ofl'crs certain advantages in handling certain classes of work, but a class of work which could be advantageously handled by one type of machine could not generally be advantageously ol economically handled by another type. For example, the rotating table type of machine is employed, heretot'ore stated, for work-pieces of circular shape or for face milling, which work could not be so advantageously or economically done upon the straight reciprocating table type of machine. Therefore, no one of the heretofore-mentioned types of machine offers the advantage of being always able to employ the most efficient and most economical way of milling for all classes of work. It is, therefore, an object of the present invention to provide a work-table and means for so moving that work-table, that the sin gle compact machine may be employed in performing substantially the same movements of the work-pieces as in any one of the heretofore-mentioned types of machine.

Another object of the invention is to ac complish a return of the finished workpieces to initial position without such return describing a path of the work-pieces underneath the cutter, and thus avoiding any possible marring or injury to the finished work-pieces by the cutter, such as may possibly occur in the straight reciprocating table type of machine hereto referred to in which the work-table in its return to initial position returns the finished work-piece again underneath the cutter.

Still another object of my invention is to provide for a feeding and traverse of the work-table in either direction underneath the cutter.

Further objects of my invention will appear from the detailed description of a preferred embodiment thereof later to be given.

To accomplish the objects heretofore stated and other objects which will later appear in the detailed description of a preferred embodiment of my improved machine and of various methods of operating thereof, my improved machine includes a work-table and driving means therefor whereby any of the following methods of operation may be performed at will:

(1) A reciprocation of the table in a straight path underneath the cutter,

(a) with a slow feeding movement coir tinuously in either direction, or

(b) with an intermittently slow feeding and rapid traversing movement continuously in either direction, or

(c) with an intermittently slow feeding movement and a rapid traverse, and a rapid return;

(2) A rotation of the table without rcciprocation either slowly or rapidly continuously, or intern'iittently with a slow feed and rapid traverse;

(3) A reciprocation of the table in forward feeding and traversing movement and return to initial position, and then a partial rotation or indexing of the table to present a new work-piece in proper relation to the cutter:

(4) A reciprocation of the table in feeding and traversing moments under the cutter and after the last work-piece has advanced beyond the cutter to finished osition, and indexing movement of the tab e simultaneously with the return movement of the table in its reciprocatory path to provide a new work-piece in proper relation to the cutter.

By the movements mentioned in paragraph (1) above, all the advantages of the reciprocating table type of milling machine are present, while by the movements set forth in paragraph (2), all the advantages of the rotating table type of milling machine are present, and by the movements set forth in paragraphs (3) and (4), all the advan tages of the double swivel table type of machine are present, without the disadvantages thereof heretofore mentioned.

The partial rotative movement termed an indexing movement of the table mentioned in paragraphs (3) and (4) is distinct and for a different purpose than the complete rotation of the table set forth in paragraph (2). \Vhen the movements set forth in paragraphs and (4) are employed, any desired number of workpieces may be placed upon the table in such synnnetrical relation to the center of the table that when the table is reciprocated to pass one or a plurality of work-pieces of one side of the center beneath the cutter, partial rotations of the table through the proper degrees will successively bring the symmetrically placed work-pieces on the opposite side of the center from the first-mentioned work-pieces which have been finished, into position to be operated on by the cutter when the table is again advanced in a straight-line movement. Thus if but two work-pieces are placed upon the table one on one side of the center in position upon the first reciprocation of the table to pass beneath the cutter and the other work-piece is placed on the opposite side of the center of the table an indexing of the table through 180 degrees, after the first workpiece is finished, will bring the second work-piece in position whereby the.next reciprocation of the table will bring that work-piece beneath the cutter. If a plurality of work-pieces are symmetrically placed upon the table, the index ing movement of the table will be through a correspondingly less number of degrees.

Performing the return movement of the table in its reciprocatory path before performing the indexing movement of the table to present a new work-piece for the cutter, as

set forth in paragraph (3), is of great advantage in all cases where the removing of the finished work and the setting of a new piece of work upon the table takes a longer time than the forward cutting and return movement of the table. In cases, however. where the forward cutting and return movement of the table takes a longer time than removing work already finished from the table and setting new work thereon, it is of greater advantage to perform the indexin of the table during its return movementin the reciprocatory path, as set forth in paragraph (4) above.

This simultaneous indexing movement and return movement of the table, in addition to the saving of time involved, also returns the finished work-piece upon the table to initial position in a path, due to the indexing movement of the table, which avoids a return passage under the cutter, and therefore obviates the possibility of a marring of the finished work.

The machine provides for the various movements referred to either automatically throughout the progress of the movements after an initial hand adjustment of dog tripping mechanism or by hand operating mechanism operated at will at the various stages of the desired movements.

In the foregoing a general outline of the various table movements have been given, but a still greater variety may be obtained, as will later appear from a detailed description of an illustrative embodiment of the invention and the methods of operation thereof, by first selecting a movement best suited for a certain class of work and then adjusting the automatic trip dogs later to be referred to, which dogs co-operate with the various movement transmitting means, or by manual manipulation of the mechanisms, later to be referred to, cooperating with the movement transmitting means. All these movements, in addition to the provision of hand operation during the progress of the cycle of the movements, may thus be automatically performed if desired, and the operator has then only to attend to the removing of the finished work-pieces and the placing of the new ones.

The various features of my invention will be more fully set forth in the description, and the accompanying drawings forming part of this specification, of an illustrative embodiment thereof and of various methods of its operation, but it is to be understood that my invention as to the machine is capable of embodiment in many different forms and my invention as to the methods of milling is not limited to the illustrative machine. While, therefore, I shall illustrate my invention by the best physical embodiment known to me, such embodiment is to be re arded only as typical of many possible em odiments, and my invention is not to be confined thereto.

In the drawings like characters of reference denote corresponding parts throughout all of the views, of which- Figure 1 is a front elevation of a milling machine embodying my invention;

Fig. 2 is a side elevation thereof, looking at the left-hand side of Fig. 1;

Fig. 3 is a sectional view along the line 33 of Fig. 2;

Fig. 4 is a sectional view along 44 of Fig. 1; i

Fig. 5 is a sectional view along the line 5-5 of Fig. 1;

Fig. 6 is a sectional view along the line 6-6 of Fig. 5;

Fig. 7 is a sectional view along the line 7-7 of Figs. 5 and 6;

Fig. 8 is a sectional view along the line 88 of Fig. 5;

Fig. 9 is a sectional view along the line 9-9 of Fig. 5;

Fig. 10 is a partial end view of the righthand end of Fig. 9;

Fig. 11 is a partial side elevational view of Fig. 2 looking at the right-hand side, and showing partially in full and partially in dotted lines a detailed view of the mechanism for the ,operation of the clutches for the hand and the power feed for the reciprocating slide and for the movements of the worktable in rotation and in indexing;

Fig. 12 is a sectional view along the line 12-12 of Fig. 11;

Fig. 13 is a sectional view along the line 13-13 of Fig. 11;

Fig. 14 is a plan view of the indexing mechanism of the work-table;

Fig. 15 is a sectional view along the line 1515 of Fig. 14, showing the indexing mechanism in operative position;

Fig. 16 is a sectional view along the line 1616 of Fig. 14 showing the indexing mechanism in one position of operation;

Fig. 17 is a sectional view along the line 16-16 of Fig. 14, showing the indexing mechanism in another positionof operation;

Fig. 18 is a sectional view along the line 1818 of Fig. 14, showing the indexing mechanism in a third position of operation;

Fig. 19 is an end view of the indexing mechanism in the direction of the arrow N of Fig. 14;

Fig. 20 is a plan view of the mechanism for the operation of the indexing mechanism by hand;

Fig. 21 is a partial side view of the lefthand side of Fig. 20;

Fig. 22 is a sectional view along the lines 22-22 of Fig. 20;

Fig. 23 is a sectional view along the line 23-23 of Fig. 20;

Fig. 24 is a sectional view along the line 2424 of Fig. 20;

Fig. 25 is a sectional view along the line 2525 of Fig. 22;

Figs. 26, 27, 28 and 29 are views partially in section and partially in plan of the driving mechanism of the reciprocatin slide, of the rotatable work-table mounte therethe line on, and of the mechanism for performing the two rotative movements of the worktable in milling and indexing;

Fig. 30 is a sectional view along the line 3030 of Fig. 26;

Fig. 31 is a view partially in section and partially in elevation of the mechanism to lock the table to the reciprocating slide and of the hand and power operating indexing mechanism;

Figs. 32, 33 and 34 are diagrammatic views showing the travel of the work upon the work-table around the cutter through the simultaneous movement of the reciproeating slide and the work-table in indexing.

As will be obvious from an inspection of the drawings, the various figures thereof are drawn to varying scales for purposes of clearness.

As a preliminary to the more detailed description of the machine constituting the illustrative embodiment of my invention, it may be stated that the work-table, circular in form, is mounted for rotation upon a reciprocatory slide, which slide in its reciprocatory movement describes a straight path longitudinally of the machine, as viewed in Fig. 1, and at right angles to the plane of the drawing as viewed in Fig. 2, beneath the cutting tool shown in Fig. 2.

WVhen the work-table is to be reciprocated without rotation, to accomplish the functions, among others, of a milling machine of the type hereto referred to in paragraph (1), the circular table is to be locked to the reciprocatory slide by means of a locking pin, which may be withdrawn manually by the operator at will or may be automatically withdrawn in a manner hereinafter set forth, so as to set the circular ta le free for complete rotation in milling or or artial rotation in indexing. When the wor -table is locked to the slide and continuously reeiprocated back and forth therewith, all of the functions of the first-mentioned t pe of milling machine may be accomplishecli In addition to this continuous reciprocation of the slide with the work-table locked thereon, at either extremity of movement of the slide, the locked pin may be withdrawn and the work-table caused to partially rotate, in what is here termed an indexing movement, and thereafter again locked in position on the slide to position a different portion of the work-table in the path of the cutter, thus accomplishing the functions not heretofore accomplished by the types of milling machine already referred to.

Considering now the circular work-table locked to the slide, work, fastened to the table some distance off center, may be cut by imparting a feeding movement in a straight line to the slide. During this process of cutting, work can be set at some other place on the table and in such a position as will bring the work in proper relation to the cutter when the work-table is indexed after the first work piece has been finished. For example, for two pieces of work, placed ofi center and symmetrically with respect to the center of the table, and one on that side of the center in line with the cutter, and the other on the opposite side of the center, when the slide has been fed forward with the table locked thereto so as to bring the first-mentioned piece of work beneath and beyond the cutter so as to be finished thereby, the slide with the work-table still locked thereto may be returned to initial position and thereafter the lock-pin withdrawn and the table indexed 180 degrees to bring the unfinished work into that path described by the first-mentioned work, the table again locked to the slide and the slide again advanced to feed the table and the new workpiece beneath the cutter, during which advance of the new work-piece, the finished work-piece may be removed and another work-piece placed upon the table in the position as before. Or, after the table has completed its first advance to bring the firstmentioned work-piece beneath and beyond the cutter to finished condition, the locked pin may be withdrawn and the indexing movement started sin'iultaneously with the return of the slide and table to initial position, thus saving time in the indexing, and accomplishing the additional function of returning the finished work-piece in a circular path avoiding the cutter instead of a return along its original path as in the first-mentioned operation. \Vhen three work-pieces are symmetrically placed upon the table, the

indexing movement referred to will be 120 degrees, and correspondingly less in proportion to the number of work-pieces.

The slide may also be maintained stationary, the work-table released from its locked relation thereto, and the work table rotated thereon for continuous milling work-pieces in a circular path. and the machine as thus operated accomplishes all the functions of the second type of milling machine heretofore referred to.

It will be observed from this outline that there are three possible driving movements; the reciprocatory movement of the slide in a straight path beneath the cutter, the continuous rotation of the work-table thereon for circular milling, and the partial rotation of the table,- or indexing movement. All three of these drives are taken from a single main driving shaft. In the first two drives, provision is made for a slow feed, while the work is passing the cutter and a quick traverse to advance the work-piece to cutting position. and a quick return of the table to initial position, while the third drive. for indexing, is one of constant speed. Provision is also made for setting these possible in a machine 0 three drives into operation either manually or automatically through trip dogs adjustable upon the reciprocating slide and the rotating table and co-operating with the driving mechanism in the body of the machine;

and like provision is made for locking or releasing the rotatable table upon this slide either manually or by adjustable trip dogs.

By the adjustment of the trip do s a great variety of automatic timings of t e movements of slow feed, rapid traverse, return of the table and indexing of the table, can be had to correspond to the necessities of the work.

Means are also rovided for disconnecting the power drives for the reciprocation of the slide and the rotation and indexing of the work-table, and for manually driving these parts, such provision being of advantage particularly in setting the trip dogs for the various timing operations when the power drive is restored.

The slow and fast feeds are not only taken from a single main driving shaft, as already stated, but such movements are also trans mitted to a single intermediate transmission shaft from which single intermediate transmission shaft branch driving shafts and co-operating driving mechanisms transmit the drives to the reciprocatory slide and the rotatable table in circular milling and in indexing.

In order to provide as few clutch operations as possible, provision is made, by way of a differential speed transmission mechanism, for continuing the slow drive and superimposingthereon at will the rapid drive.

To provide for as few 0 crating parts as this character, provision Is also made for a single reversing mechanism operative upon both the slow and fast movement in the milling drives mentioned, namely, the straight drive for the reciprocatory slide for straight milling and the drive for rotating the work-table in circular milling.

To meet the various conditions under which the cutting tool has to work, provision is also made by way of change gears, to vary the slow or fast drive.

As already stated, two movements are given to the rotatable work-table; one, a continuous rotation in circular milling, and the other, a partial rotation, in indexin during both of which movements. it is o vious that the table must be unlocked for movement upon the slide: and provision is made for locking the table against the indexing movement while a continuous rotary movement is being performed. and vice versa,-that is, complementary locking in the indexing and circular table driving mechanisms.

The detailed description of the illustrative embodiment of the invention which is to follow relates to these various mechanisms thus outlined.

Proceeding now to a detailed description of the illustrative machine, numeral 1 (Fig. 1) denotes in general the frame or housing of the machine. At one side thereof, the left-hand side as viewed in Fig. 2, is the spindle column 2, while the right-hand side thereof provides a housing for the various driving mechanisms, later to be described, and a support for the reciprocating slide and the rotatable table 61 thereon, later to be described in detail.

The cutter spindle column and the power transmission therethrough to operate the cutter spindle may be of the usual or any preferred construction, and the details thereof constituting no partof my invention, are not deemed essential to illustrate or describe.

The main power shaft of the machine is indicated by the numeral 3 (Fig. 2), operated in any suitable manner, a pulley 3 being here illustrated. and the power being transmitted thereto from, any desired prime mover.

Motion for the various driving mechanisms is taken off the main pulley shaft'3 (Fig. 2), which is running at a constant speed, and transmitted to pulley 4 of the main drive or feed shaft 5, which at one end is journalled in a bearing 6 on the frame 1 (Fig. 2) and at the other end is journalled in a gear box 10 (Fig. 26).

Pulley 4 is mounted loose on the shaft 5 and is adapted to be connected by means of a friction clutch 7 (Fig. 2) to said shaft, to transmit rotary movement to said shaft. The friction clutch is under the control of a foot treadle 8, which is located conveniently to the operator, as shown in Fig. 2, and which foot treadle is connected with the clutch 7 by rod 8 and lever 9. Feed gear box 10, shown in outline in Fig. 1, is bolted to frame 1, and is rovided with two bushings 11 and 12 (F1 1,5 and 26), which form two additionaT bearin for the shaft 5 which extends through t e gear box, as shown in Fig. 26.

Rotatably mounted on 11, as shown in Figs. 5 and 26, is a spur gear 13, whichis provided with clutch teeth 14. Numeral 15 (Figs. 5 and 26) indicates a co-operating toothed clutch turning with andsliding on shaft 5. On the other end of the shaft is mounted and fixed thereon a worm 16 (Fig. 5) which meshes with worm-wheel 17 (Figs. 5 and 26). This worm-wheel is provided with clutch teeth 18 and is free to revolve on shaft 19 (Figs. 9 and 26) which is journalled in hearings on the gear box 10. Clutch 20 turns with and slides on shaft 19 and can be brought into mesh with wormwheel 17. A bevelled pinion 21, fixed on 

